For decades, it has been conventional in connection with heat exchangers such as a steam condenser to employ the concept of a cascading air cooler section with controlled velocities to preclude stagnation. Air coolers in a condenser cool any non-condensable gases that have entered the condenser and before they are exited to thereby condense as much of the steam associated with these gases as possible. Air coolers take advantage of the pressure gradient inherent within a tube bundle between the inlet and outlet water ends to provide a positive flow from the hot end to the cold end with the air vapor outlets located at the cold end. In a conventional steam condenser, the air cooler section has a hole of significant size centrally located in each of the tube support plates. The area displaced by the hole is an untubed region of the tube bundle.
In some designs of multi-pass condensers, the air cooler is located in the cold water pass only. The air cooler openings in the tube support plates must often be located in a progressively elevated manner along the length of the cold water pass from its warm end to its cold end. As a result, a substantial area of the tube bundle must be left untubed to provide for this progressive variation in air cooler opening location along the length of the cold water pass. The present invention eliminates this untubed area since, no matter where the location of the air cooler opening occurs, the opening will be fully tubed while at the same time permitting proper operation of the air cooler.